Water electrolysis stack

Abstract

To provide a water electrolysis stack capable of stripping gas that forms as bubbles on the surface of a power feeder.SOLUTION: A water electrolysis stack comprises a membrane electrode structure 30 including an electrolyte membrane 40 and a plate-shaped power feeder 42 provided on one side in the thickness direction of the electrolyte membrane 40, a water inlet for introducing water supplied from outside, a water flow path member 46 arranged facing the power feeder 42 and provided with a water flow path 50b that guides water introduced into the water inlet along the surface direction of the power feeder 42, and a pressurizing section that pressurizes water to the water inlet. The pressurizing section pulsates the water flowing through the water flow path 50b along the surface direction of the power feeder 42 by continuously changing the pressurized delivery amount of water.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a water electrolysis stack. [Background technology]

[0002] The following patent document discloses a technique for preventing a decrease in electrolysis efficiency due to adhesion of bubbles generated by electrolysis to the surface of an electrode (power supplier). Specifically, a gas-liquid mixture of an electrolytic solution and bubbles is introduced into an electrolytic cell, and the bubbles in the introduced gas-liquid mixture are caused to collide with gas (bubbles) generated on the surface of the electrode (power supplier) in the electrolytic cell.

[0003] Furthermore, the following Patent Document discloses a method for adjusting bubbles in a gas-liquid mixture introduced into an electrolytic cell. Specifically, the flow rate of the gas-liquid mixture introduced into the electrolytic cell is adjusted. The diameter of bubbles in the gas-liquid mixture introduced into the electrolytic cell is adjusted by the internal pressure of the electrolytic cell. The ratio of bubbles in the gas-liquid mixture introduced into the electrolytic cell is adjusted by the amount of bubbles supplied to the electrolytic solution. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-001745 Summary of the Invention [Problem to be solved by the invention]

[0005] When bubbles remain in the water electrolysis stack, the electrolysis efficiency tends to decrease. Therefore, it is desired to separate gas generated as bubbles from the surface of the power supply without actively mixing the bubbles into the water introduced into the water electrolysis stack.

[0006] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0007] A first aspect of the present disclosure is a water electrolysis stack comprising: a membrane electrode assembly including an electrolyte membrane and a plate-shaped current supplier provided on one of both sides of the electrolyte membrane in a thickness direction; a water inlet portion for introducing water supplied from an external source; and a water flow path member disposed opposite the current supplier and provided with a water flow path for guiding the water introduced into the water inlet portion along a surface direction of the current supplier, wherein the water electrolysis stack further comprises a pumping portion for pumping the water toward the water inlet portion, and the pumping portion continuously changes the amount of water pumped, thereby pulsating the water flowing through the water flow path along the surface direction of the current supplier.

[0008] A second aspect of the present disclosure is a water electrolysis stack comprising: a membrane electrode assembly including an electrolyte membrane and a plate-shaped current supplier provided on one of both sides of the electrolyte membrane in a thickness direction; a water inlet portion for introducing water supplied from an external source; and a water flow path member disposed opposite the current supplier and provided with a water flow path that guides the water introduced into the water inlet portion along a surface of the current supplier, wherein the water electrolysis stack further comprises a water flow rate adjuster disposed in the water inlet portion and adjusts the amount of water introduced into the water inlet portion, and the water flow rate adjuster continuously changes the amount of water, thereby pulsating the water flowing through the water flow path along the surface of the current supplier. [Effects of the Invention]

[0009] According to an aspect of the present disclosure, gas generated as bubbles on the surface of the current collector by electrolysis can be separated from the current collector by the pulsation of water. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a water electrolysis system according to a first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the water electrolysis cell. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a diagram showing a water electrolysis system according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] 1 is a diagram showing a water electrolysis system 10 according to a first embodiment. The water electrolysis system 10 includes a water electrolysis stack 100, a water circulation flow path 102, and a water supply source 104.

[0012] The water electrolysis stack 100 includes a stack body 11. The stack body 11 includes a plurality of water electrolysis cells 12, a pair of terminal plates 16a, 16b, a pair of insulating plates 18a, 18b, a pair of end plates 20a, 20b, a water inlet 39a, and a water outlet 39b. The water electrolysis cells 12 are stacked. The stacking direction of the water electrolysis cells 12 is the direction of gravity, but is not limited to this. Details of the water electrolysis cells 12 will be described later.

[0013] The terminal plate 16a, the insulating plate 18a, and the end plate 20a are arranged in this order upward at one end (upper end) of the stack 14 in the stacking direction. The terminal plate 16b, the insulating plate 18b, and the end plate 20b are arranged in this order downward at the other end (lower end) of the stack 14 in the stacking direction. The end plates 20a, 20b are fastened together by a pressing mechanism such as a plurality of tie rods extending in the stacking direction of the water electrolysis cells 12. The stack body 11 is maintained in a fastened state in the stacking direction.

[0014] A high-pressure gas outlet hole 38c is provided in the stack body 11. The high-pressure gas outlet hole 38c penetrates the multiple water electrolysis cells 12, the terminal plate 16a, the insulating plate 18a, and the end plate 20a. A pipe (not shown) is connected to the high-pressure gas outlet hole 38c in the end plate 20a. The pipe (not shown) is provided with a back pressure mechanism capable of restricting gas discharge.

[0015] The water inlet 39a is provided in the water electrolysis cell 12 located at one end (lower end) of the multiple water electrolysis cells 12 in the stacking direction. The water inlet 39a introduces water supplied from outside the stack body 11. The water outlet 39b is provided in the water electrolysis cell 12 located at the other end (upper end) of the multiple water electrolysis cells 12 in the stacking direction. The water outlet 39b delivers water to the outside of the stack body 11.

[0016] The water circulation flow path 102 is a passage for flowing water through the stack main body 11. The water circulation flow path 102 is connected to the stack main body 11. The water circulation flow path 102 includes a first flow path section 102a and a second flow path section 102b. The first flow path section 102a connects the water inlet section 39a and the water supply source 104. The second flow path section 102b connects the water outlet section 39b and the water supply source 104.

[0017] The water supply source 104 is a source of water supplied to the stack body 11. The water supply source 104 may be a gas-liquid separator that separates water from gas in the water. Alternatively, the water supply source 104 may be a tank that stores water.

[0018] Fig. 2 is an exploded perspective view of the water electrolysis cell 12. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. As shown in Figs. 2 and 3, the water electrolysis cell 12 includes a substantially disk-shaped membrane electrode assembly 30, and a first separator 32 and a second separator 34 that sandwich the membrane electrode assembly 30 and other components. A frame member 36 is disposed between the first separator 32 and the second separator 34 so as to surround the membrane electrode assembly 30 and other components.

[0019] The frame member 36 is generally ring-shaped, and seal members 37a, 37b (see FIG. 3) are provided on both sides of the frame member 36. One radial end (arrow B direction) of the frame member 36 is provided with a water inlet hole 38a extending along the stacking direction (arrow A direction). The water inlet holes 38a of the stacked water electrolysis cells 12 communicate with each other. The water inlet hole 38a is connected to a water inlet portion 39a.

[0020] A water outlet hole 38b extending along the stacking direction (arrow A direction) is provided at the other radial end (arrow B direction) of the frame member 36. The water outlet hole 38b is formed to discharge a mixed fluid containing unreacted water that has not been electrolyzed. The water outlet holes 38b of the stacked water electrolysis cells 12 communicate with each other. The water outlet hole 38b is connected to a water outlet portion 39b.

[0021] Each water electrolysis cell 12 is provided with a high-pressure gas outlet hole 38c that penetrates its radial center along the stacking direction. The high-pressure gas outlet holes 38c of the stacked water electrolysis cells 12 are in communication with each other. The high-pressure gas outlet hole 38c of the water electrolysis cell 12 located at the other end (upper end) of the multiple water electrolysis cells 12 in the stacking direction is in communication with the high-pressure gas outlet hole 38c of the terminal plate 16a ( FIG. 1 ). The gas supplied to the high-pressure gas outlet hole 38c is discharged at a pressurized state of, for example, 1 MPa to 80 MPa.

[0022] The membrane electrode assembly 30 is composed of an electrolyte membrane 40, a first electrode catalyst layer 42a, a second electrode catalyst layer 44a, a first power supply 42, and a second power supply 44. The first electrode catalyst layer 42a and the first power supply 42 are provided on one of both sides of the electrolyte membrane 40. The second electrode catalyst layer 44a and the second power supply 44 are provided on the other of both sides of the electrolyte membrane 40.

[0023] The first electrode catalyst layer 42a may be simply referred to as the electrode catalyst layer 42a. The same applies to the second electrode catalyst layer 44a. The first power supply 42 may be simply referred to as the power supply 42. The same applies to the second power supply 44.

[0024] The electrolyte membrane 40 may be an anion exchange membrane or a proton exchange membrane. When the electrolyte membrane 40 is an anion exchange membrane, the water used for electrolysis is alkaline water. When the electrolyte membrane 40 is an anion exchange membrane, the electrode catalyst layer 42a and the power supplier 42 are the anode, and the electrode catalyst layer 44a and the power supplier 44 are the cathode, the gas supplied to the high-pressure gas outlet hole 38c is hydrogen produced by water electrolysis. In this case, the mixed fluid discharged from the water outlet portion 39b (see FIG. 1) contains unreacted water that has not been electrolyzed and oxygen produced by electrolysis. On the other hand, when the electrolyte membrane 40 is an anion exchange membrane, the electrode catalyst layer 42a and the power supplier 42 are the cathode, and the electrode catalyst layer 44a and the power supplier 44 are the anode, the gas supplied to the high-pressure gas outlet hole 38c is oxygen produced by electrolysis. In this case, the mixed fluid discharged from the water outlet 39b (see FIG. 1) contains unreacted water that has not been electrolyzed and hydrogen that has been produced by electrolysis.

[0025] When the electrolyte membrane 40 is a proton exchange membrane, the water used for electrolysis is water (e.g., pure water) containing a predetermined amount of impurities (ions) or less. When the electrolyte membrane 40 is a proton exchange membrane, the electrode catalyst layer 42a and the power supply 42 are the anode, and the electrode catalyst layer 44a and the power supply 44 are the cathode, the gas supplied to the high-pressure gas outlet hole 38c is hydrogen produced by electrolysis. In this case, the mixed fluid discharged from the water outlet 39b (see FIG. 1) contains unreacted water that has not been electrolyzed and oxygen produced by electrolysis. On the other hand, when the electrolyte membrane 40 is a proton exchange membrane, the electrode catalyst layer 42a and the power supply 42 are the cathode, and the electrode catalyst layer 44a and the power supply 44 are the anode, the gas supplied to the high-pressure gas outlet hole 38c is oxygen produced by electrolysis. In this case, the mixed fluid discharged from the water outlet 39b (see FIG. 1) contains unreacted water that has not been electrolyzed and hydrogen that has been produced by electrolysis.

[0026] A first electrode catalyst layer 42a is provided on a portion of one surface of the electrolyte membrane 40. A second electrode catalyst layer 44a is provided on a portion of the other surface of the electrolyte membrane 40. The first electrode catalyst layer 42a and the second electrode catalyst layer 44a are formed, for example, in a ring shape.

[0027] The electrolyte membrane 40 has a covered portion 40a covered with a pair of electrode catalyst layers 42a, 44a, and an exposed portion 40b exposed from the electrode catalyst layers. In the water electrolysis cell 12, the area of ​​the covered portion 40a along the stacking direction forms an electrolysis region.

[0028] The inner and outer diameters of the first and second power feeders 42, 44 are set so that they are disposed in the electrolysis region. Therefore, the radially central ends of the first and second power feeders 42, 44 are respectively disposed at a radial distance from the high-pressure gas outlet hole 38c.

[0029] A frame 42e is fitted onto the outer periphery of the first current feeder 42. The frame 42e is configured to be denser than the first current feeder 42. Note that by configuring the outer periphery of the first current feeder 42, which extends radially outward from the electrolysis region, to be dense, the outer periphery can also be used as the frame 42e.

[0030] The first separator 32 and the frame member 36 form a first chamber 45an (see FIG. 3) between the first separator 32 and the electrolyte membrane 40, in which a first power supply body 42 is housed. The second separator 34 and the frame member 36 form a second chamber 45ca (see FIG. 3) between the second separator 34 and the electrolyte membrane 40, in which a second power supply body 44 is housed.

[0031] A water flow path member 46 is interposed between the first separator 32 and the first current feeder 42 (first chamber 45an), and a protective sheet member 48 is interposed between the first current feeder 42 and the first electrode catalyst layer 42a. The water flow path member 46 is disposed facing the first current feeder 42. An inlet protrusion 46a and an outlet protrusion 46b that face each other in the radial direction are formed on the outer periphery of the water flow path member 46.

[0032] As shown in Figure 3, the inlet protrusion 46a is formed with a supply connection passage 50a that communicates with the water inlet hole 38a, and the supply connection passage 50a communicates with a water flow passage 50b. The water flow passage 50b is a flow passage formed in the water flow passage member 46 and extends along the surface of the first power supply body 42. The water flow passage 50b guides water in a direction along the surface of the first power supply body 42 (horizontal direction). A plurality of holes 50c communicate with the water flow passage 50b, and the holes 50c open toward the first power supply body 42. The outlet protrusion 46b is formed with a discharge connection passage 50d that communicates with the water flow passage 50b, and the discharge connection passage 50d communicates with the water outlet hole 38b.

[0033] As shown in Figures 2 and 3, the inner periphery of the protective sheet member 48 is positioned inward from the inner periphery of the first current feeder 42, and the outer periphery is positioned at the same position as the outer periphery of the electrolyte membrane 40 and the frame portion 42e. The protective sheet member 48 is composed of a central portion 48a and a frame portion 48b. The central portion 48a is surrounded by the frame portion 48b. The central portion 48a faces the covering portion 40a. The central portion 48a is disposed within the electrolysis region. The outer edge of the electrolysis region and the outer edge of the central portion 48a coincide with each other, but this is not limited to this. A plurality of communication holes 48c are formed in the central portion 48a. The frame portion 48b is positioned radially outward from the central portion 48a. For example, rectangular holes (not shown) are formed in the frame portion 48b.

[0034] A substantially cylindrical communicating hole body 52 surrounding the high-pressure gas outlet hole 38c is disposed radially center between the first separator 32 and the electrolyte membrane 40. Note that hereinafter, the water flow path member 46, the first power feeder 42, and the protective sheet member 48 may be collectively referred to as the water supply side member. In this case, the communicating hole body 52 is disposed between the high-pressure gas outlet hole 38c and the water supply side member in the radial direction of the high-pressure gas outlet hole 38c.

[0035] The communication-hole body 52 includes an inner pipe member 54 made of a porous material facing the high-pressure gas outlet hole 38c, and an outer pipe member 55 disposed between the inner pipe member 54 and the water supply-side member. As shown in Fig. 3, storage chambers 55a and 55b are provided on the side of the outer pipe member 55 facing the inner pipe member 54. The storage chambers 55a and 55b are formed by cutting out rings on the radially central side of the outer pipe member 55 and on both ends in the axial direction (stacking direction), and seal members (O-rings) 56a and 56b are disposed therein, surrounding the high-pressure gas outlet hole 38c. This seals the high-pressure gas outlet hole 38c from the first chamber 45an (the side of the first power feeder 42).

[0036] As shown in FIGS. 2 and 3, on the side of the outer pipe member 55 facing the water supply side member, a groove 55s in which a protective sheet member 48 is disposed is formed on the end surface facing the electrolyte membrane 40.

[0037] The second power supply body 44 and a load-applying mechanism 58 that presses the second power supply body 44 against the second electrode catalyst layer 44a are disposed in the electrolysis region within the second chamber 45ca. The load-applying mechanism 58 includes a conductive elastic member such as a leaf spring 60, and the leaf spring 60 applies a load to the second power supply body 44 via a metal leaf spring holder (shim member) 62. In addition to the leaf spring 60, a disc spring, a coil spring, or the like can also be used as the elastic member.

[0038] A resin sheet 68, for example, is disposed radially closer to the center than the electrolysis region in the second chamber 45ca as an insulating member that covers the exposed portion 41b of the electrolyte membrane 40. The resin sheet 68 is set to have approximately the same thickness as the second power feeder 44 and is ring-shaped with the high-pressure gas outlet hole 38c formed in approximately the radial center.

[0039] The second power supply body 44 and the surface of the resin sheet 68 facing the plate spring holder 62 are covered with a conductive sheet 66. The conductive sheet 66 is, for example, ring-shaped with the high-pressure gas outlet hole 38c formed in approximately the center in the radial direction.

[0040] A tubular member 70 is disposed between the load-applying mechanism 58 and the high-pressure gas outlet hole 38c in the radial direction, and between the conductive sheet 66 and the second separator 34 in the stacking direction. The tubular member 70 has a cylindrical shape and is made of a conductive material such as metal, and has the high-pressure gas outlet hole 38c formed in its center. An exhaust passage 71 that connects the second chamber 45ca and the high-pressure gas outlet hole 38c is formed in one end surface of the tubular member 70 facing the second separator 34.

[0041] As described above, by disposing the through-hole body 52 (outer pipe member 55) and the tubular member 70 between the first separator 32 and the second separator 34, it is possible to improve the load-bearing capacity of the water electrolysis cell 12 near the high-pressure gas outlet hole 38c. In addition, the through-hole body 52 and the tubular member 70 sandwich the portions of the electrolyte membrane 40, the resin sheet 68, and the conductive sheet 66 that are radially closer to the center than the electrolysis region (portions near the high-pressure gas outlet hole 38c).

[0042] A seal member (O-ring) 72 is disposed radially outside the electrolysis region in the second chamber 45ca so as to be interposed between the electrolyte membrane 40 and the second separator 34. A pressure-resistant member 74 is disposed on the outer periphery of the seal member 72. The pressure-resistant member 74 has a generally ring shape, and its outer periphery fits into the inner periphery of the frame member 36.

[0043] The water electrolysis cell 12 is provided with a conductive path electrically connecting the second separator 34 to the tubular member 70, the conductive sheet 66, and the second power supply 44, and a conductive path electrically connecting the second separator 34 to the leaf spring 60, the leaf spring holder 62, the conductive sheet 66, and the second power supply 44.

[0044] The stack body 11 is provided with the water electrolysis cell 12 basically configured as described above.

[0045] As shown in FIG. 1, the water electrolysis stack 100 further includes a pumping unit 106 in addition to the stack body 11.

[0046] The pressure-feeding unit 106 is provided separately from the stack main body 11. Specifically, the pressure-feeding unit 106 is provided in the first flow path portion 102a. The pressure-feeding unit 106 pressure-feeds water to the water introduction portion 39a. The pressure-feeding unit 106 may be a pump. The type of pump is not particularly limited. Types of pumps include centrifugal pumps, turbine pumps, cascade pumps, piston pumps, plunger pumps, diaphragm pumps, wing pumps, and injection pumps.

[0047] The pumping unit 106 continuously changes the pumping rate of the water. For example, the pumping unit 106 periodically changes between a first pumping rate and a second pumping rate that is greater than the first pumping rate. This causes pulsation in the water flowing inside the stack body 11. In other words, the pressure and flow rate of the water flowing inside the stack body 11 periodically fluctuate. As shown in FIG. 3, the pulsation reaches the water flow path 50b via the water inlet hole 38a and the supply connecting path 50a in this order. The pulsation that reaches the water flow path 50b propagates in a direction along the surface of the first power feed body 42 (horizontally) and reaches the water outlet hole 38b via the discharge connecting path 50d. The pulsation that reaches the water outlet hole 38b is supplied from the water outlet unit 39b to the second flow path portion 102b of the water circulation flow path 102, as shown in FIG. 1.

[0048] In this embodiment, the pumping unit 106 continuously changes the amount of water pumped, thereby pulsating the water flowing through the water flow path 50b along the surface direction of the power supply body (first power supply body) 42. This allows gas bubbles generated on the surface of the power supply body (first power supply body) 42 by electrolysis to be separated from the power supply body by the pulsation of the water.

[0049] [Second embodiment] In this embodiment, descriptions that overlap with those in the first embodiment will be omitted. Fig. 4 is a diagram showing a water electrolysis system 10 according to a second embodiment. In Fig. 4, the same components as those described in the first embodiment are denoted by the same reference numerals.

[0050] In this embodiment, the pumping unit 106 operates at a rated output. The amount of water pumped from the pumping unit 106 to the water introduction unit 39a per unit time is approximately constant.

[0051] In the present embodiment, the water electrolysis system 10 further includes a water volume adjustment unit 108. In FIG. 4 , the water volume adjustment unit 108 is provided in the water inlet 39a, but this is not limiting. For example, the water volume adjustment unit 108 may be provided in the first flow path 102a between the pumping unit 106 and the stack main body 11. The water volume adjustment unit 108 adjusts the volume of water introduced into the water inlet 39a. The water volume adjustment unit 108 may be a valve (valve device). The valve is not particularly limited as long as it is capable of adjusting the flow rate. Examples of such valves include a butterfly valve, a gate valve, a globe valve, and a ball valve. The water volume adjustment unit 108 continuously changes the volume of water introduced into the water inlet 39a. This causes pulsation in the water flowing inside the stack main body 11. As described with reference to FIG. 3, the pulsation that reaches the water flow path 50b propagates in a direction along the surface of the first power supply body 42 (horizontally) and reaches the water outlet hole 38b via the discharge connecting path 50d.

[0052] In this embodiment, the water volume adjuster 108 continuously changes the amount of water introduced into the water inlet 39a, thereby pulsating the water flowing through the water flow path 50b along the surface of the power supply body (first power supply body) 42. This allows gas bubbles generated on the surface of the power supply body (first power supply body) 42 by electrolysis to be separated from the power supply body by the pulsation of the water.

[0053] In this embodiment, water is supplied to the water volume regulator 108 from the pumping unit 106, which operates at a rated output. This allows the water to pulsate regularly.

[0054] In this embodiment, pumping unit 106 may change the amount of water pumped at a predetermined cycle. In this case, water volume adjustment unit 108 can make the water pulsate more finely by changing the amount of water introduced into water introduction unit 39a at a cycle shorter than the cycle of pumping unit 106. Alternatively, water volume adjustment unit 108 can make the water pulsate irregularly by changing the amount of water introduced into water introduction unit 39a at a random cycle different from the cycle of pumping unit 106.

[0055] In the present embodiment, the water electrolysis system 10 further includes a pressurizing unit 110 that pressurizes the water introduced into the water inlet 39a. The pressurizing unit 110 applies water pressure to the water flowing through the first flow path portion 102a. This increases the degree of change in the pressure and flow rate of the water flowing inside the stack body 11. In FIG. 4, the pressurizing unit 110 is provided in a portion of the first flow path portion 102a between the water supply source 104 and the pumping unit 106, but it may also be provided in a portion between the stack body 11 and the pumping unit 106. In the present embodiment, one of the pumping unit 106 and the pressurizing unit 110 does not necessarily have to be provided. The pressurizing unit 110 may also be provided in the first flow path portion 102a of the first embodiment.

[0056] The following additional notes are further disclosed regarding the above embodiment.

[0057] (Appendix 1) The water electrolysis stack (100) of the present disclosure is a water electrolysis stack including: a membrane electrode assembly (30) including an electrolyte membrane (40) and a plate-shaped current supplier (42) provided on one of both sides in the thickness direction of the electrolyte membrane; a water inlet (39a) for introducing water supplied from an external source; and a water flow path member (46) disposed opposite the current supplier and provided with a water flow path (50b) for guiding the water introduced into the water inlet along a surface direction of the current supplier, the water electrolysis stack including a pumping unit (106) for pumping the water toward the water inlet, and the pumping unit continuously changes the amount of water pumped, thereby pulsating the water flowing through the water flow path along the surface direction of the current supplier.

[0058] (Appendix 2) The water electrolysis stack of the present disclosure is a water electrolysis stack comprising: a membrane electrode assembly including an electrolyte membrane and a plate-shaped current supplier provided on one of both sides of the electrolyte membrane in a thickness direction; a water inlet portion for introducing water supplied from an external source; and a water flow path member disposed opposite the current supplier and provided with a water flow path for guiding the water introduced into the water inlet portion along a surface direction of the current supplier, wherein the water electrolysis stack further comprises a water flow rate adjustment unit (108) provided in the water inlet portion for adjusting the amount of water introduced into the water inlet portion, and the water flow rate adjustment unit pulsates the water flowing through the water flow path along the surface direction of the current supplier by continuously changing the amount of water.

[0059] (Appendix 3) In the water electrolysis stack according to Supplementary Note 1 or 2, the electrolyte membrane, the power supply element, and the water flow path member may be stacked in a gravity direction, and the water flow path may extend horizontally.

[0060] (Appendix 4) In the water electrolysis stack according to Supplementary Note 2, the water flow rate regulator may be supplied with the water from a pumping unit operating at a rated output.

[0061] (Appendix 5) The water electrolysis stack according to Supplementary Note 1 or 2 may further include a pressurizing unit (110) that pressurizes the water introduced into the water introducing unit.

[0062] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0063] 10...water electrolysis system 30...membrane electrode assembly 39a...Water introduction part 40...Electrolyte membrane 42... power supply body (first power supply body) 46... water flow path member 50b...water flow path 100...water electrolysis stack 106... Pressure feeding section 108... Water volume adjustment section 110...Pressure unit

Claims

1. a membrane electrode assembly including an electrolyte membrane and a plate-shaped current feeder provided on one of both sides of the electrolyte membrane in a thickness direction; a water inlet for introducing water supplied from the outside; a water flow path member disposed opposite the power supply body and having a water flow path for guiding the water introduced into the water inlet along the surface direction of the power supply body; A water electrolysis stack comprising: a pumping unit that pumps the water to the water introduction unit, The water electrolysis stack of claim 1, wherein the pumping unit continuously changes the amount of water pumped, thereby pulsating the water flowing through the water flow path along a surface direction of the power supply element.

2. a membrane electrode assembly including an electrolyte membrane and a plate-shaped current feeder provided on one of both sides of the electrolyte membrane in a thickness direction; a water inlet for introducing water supplied from the outside; a water flow path member disposed opposite the power supply body and having a water flow path for guiding the water introduced into the water inlet along the surface direction of the power supply body; A water electrolysis stack comprising: a water amount adjusting unit that is provided in the water inlet and adjusts the amount of water introduced into the water inlet; a water electrolysis stack configured to continuously change the amount of water, thereby pulsating the water flowing through the water flow path along a surface direction of the power supply element.

3. The water electrolysis stack according to claim 1 or 2, the electrolyte membrane, the power supply body, and the water flow path member are stacked in the direction of gravity, The water electrolysis stack, wherein the water flow path extends horizontally.

4. The water electrolysis stack according to claim 2, The water electrolysis stack, wherein the water volume adjustment unit is supplied with the water from a pumping unit operating at a rated output.

5. The water electrolysis stack according to claim 1 or 2, a pressurizing unit that pressurizes the water introduced into the water inlet unit.

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